Getting rid of pink in a saddle?

[Biciclista]

I'd definitely try a permanent marker. (and you might have to redo it periodically)

[SadieKate]

I've used indelible marker on the edge of the white lining of black jeans pockets and it's worked very well. I've also got some tights that have the grey flatlock stitching that need the same treatment.

Go the marker route first. Easiest and cheapest method.

[alimey]

You might be able to unpick the stitches? Otherwise I think the permanent marker will work really well.